Four kinds of polarizing film were prepared by two coloration methods of dipping and dyeing using either iodine or dye as a dichroic colorant. The optical properties of the polarizing films were compared at various concentrations of dichroic colorants and draw ratios. While iodine of low substantivity to PVA film showed little dependence of colorant content on the coloration methods, in the dye-type polarizing film dyeing method caused higher surface and bulk colorant contents than dipping method due to higher substantivity of the dichroic direct dye. However surface dichroic colorants on the film exhibited higher effectiveness in terms of observed optical properties compared with bulk dichroic colorants in the PVA film. While dye-type polarizing film showed excellent resistance to heat and humidity compared to iodine-type, coloration method did not influence significantly the optical durability of dye-type polarizing film under hot and humid condition.